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Fish & Wildlife Disease: Marine Mammals

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By Biological Threats and Invasive Species Research Program September 29, 2022

We are developing advanced tools for disease diagnosis, surveillance, risk assessment and control to support management of wildlife diseases.

Marine Mammal Disease Research

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Sea otter Elkhorn Slough National Estuarine Research Reserve (WERC)

Population Biology and Behavior of Sea Otters

WERC's sea otter researchers are developing and utilizing a variety of methodological and analytical tools to understand the causes of biological and ecological trends in sea otter populations, and to predict the ecological consequences of management practices on these populations and their ecosystems.
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Species Management Research Program, Western Ecological Research Center (WERC)
link

Population Biology and Behavior of Sea Otters

WERC's sea otter researchers are developing and utilizing a variety of methodological and analytical tools to understand the causes of biological and ecological trends in sea otter populations, and to predict the ecological consequences of management practices on these populations and their ecosystems.
Learn More
link
WERC Sea otter research in Big Sur, California

California Sea Otter Stranding Network

The California Sea Otter Stranding Network is part of the USGS effort to monitor southern sea otters (Enhydra lutris nereis) and provide data to the U.S. Fish and Wildlife Service. WERC's sea otter team works with multiple institutions and partners to report, recover, and examine stranded sea otters. In addition, instructions on how to report a stranded sea otter are included in this webpage.
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Species Management Research Program, Western Ecological Research Center (WERC)
link

California Sea Otter Stranding Network

The California Sea Otter Stranding Network is part of the USGS effort to monitor southern sea otters (Enhydra lutris nereis) and provide data to the U.S. Fish and Wildlife Service. WERC's sea otter team works with multiple institutions and partners to report, recover, and examine stranded sea otters. In addition, instructions on how to report a stranded sea otter are included in this webpage.
Learn More

Explore our science using the data below.

Sea Otter Survey Data, Carcass Recovery Data, and Blood Chemistry Data from Southwest Alaska

Three data sets are included here to aid in assessment of the sea otter population collapse in southwest Alaska. One data set consists of results of sea otter surveys conducted between 1959 and 2015 at Bering Island, Russia and a selection of western Aleutian Islands in Alaska. Sea otter counts are reduced to a comparable value of otters per linear kilometer. Another data set consists per-capita a
By
Western Ecological Research Center (WERC)

Necropsy reference number and summary collection information for Washington state population of northern sea otters examined during 1989-2010

Morbillivirus epidemics in marine mammals first gained prominence in 1988 when an outbreak of phocine distemper virus (PDV) occurred in European harbor seals (Phoca vitulina vitulina). Prior to 2001, all serosurveys for morbilliviruses in sea otters (Enhydra lutris) in California, Washington and Alaska documented a 0% seroprevalence. The first published serodetections of morbillivirus in sea otter
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, National Wildlife Health Center

Explore our science using the publications below.

New insights into dietary management of polar bears (Ursus maritimus) and brown bears (U. arctos)

Although polar bears (Ursus maritimus) and brown bears (U. arctos) have been exhibited in zoological gardens for centuries, little is known about their nutritional needs. Multiple recent studies on both wild and captive polar bears and brown bears have found that they voluntarily select dietary macronutrient proportions resulting in much lower dietary protein and higher fat or digestible carbohydr
Authors
Charles T. Robbins, Troy N Tollefson, Karyn D. Rode, Joy Erlenbach, Amanda J. Ardente
By
Ecosystems Mission Area, Alaska Science Center

An integrated population model for southern sea otters

Southern sea otters (Enhydra lutris nereis) have recovered slowly from their near extinction a century ago, and their continued recovery has been challenged by multiple natural and anthropogenic factors. Development of an integrated population model (IPM) for southern sea otters has been identified as a management priority, to help in evaluating the relative impacts of known threats and guide best
Authors
M. Tim Tinker, Lilian P. Carswell, Joseph A. Tomoleoni, Brian B. Hatfield, Michael D. Harris, Melissa A. Miller, Megan E. Moriarty, Christine K. Johnson, Colleen Young, Laird A. Henkel, Michelle M. Staedler, A. Keith Miles, Julie L. Yee
By
Ecosystems Mission Area, Western Ecological Research Center (WERC)

Energetic and health effects of protein overconsumption constrain dietary adaptation in an apex predator

Studies of predator feeding ecology commonly focus on energy intake. However, captive predators have been documented to selectively feed to optimize macronutrient intake. As many apex predators experience environmental changes that affect prey availability, limitations on selective feeding can affect energetics and health. We estimated the protein:fat ratio of diets consumed by wild polar bears us
Authors
Karyn D. Rode, Charles T. Robbins, Craig A. Stricker, Brian D. Taras, Troy N Tollefson
By
Ecosystems Mission Area, Alaska Science Center, Fort Collins Science Center

Sea otter population collapse in southwest Alaska: Assessing ecological covariates, consequences, and causal factors

Sea otter (Enhydra lutris) populations in southwest Alaska declined substantially between about 1990 and the most recent set of surveys in 2015. Here we report changes in the distribution and abundance of sea otters, and covarying patterns in reproduction, mortality, body size and condition, diet and foraging behavior, food availability, health profiles, and exposure to environmental contaminants

Authors
M. Tim Tinker, James L. Bodkin, Lizabeth Bowen, Brenda Ballachey, Gena Bentall, Alexander Burdin, Heather Coletti, George G. Esslinger, Brian B. Hatfield, Michael C. Kenner, Kimberly A. Kloecker, Brenda Konar, A. Keith Miles, Daniel Monson, Michael J. Murray, Ben Weitzman, James A. Estes
By
Ecosystems Mission Area, Alaska Science Center, Western Ecological Research Center (WERC)

Exposure to domoic acid is an ecological driver of cardiac disease in southern sea otters

Harmful algal blooms produce toxins that bioaccumulate in the food web and adversely affect humans, animals, and entire marine ecosystems. Blooms of the diatom Pseudo-nitzschia can produce domoic acid (DA), a toxin that most commonly causes neurological disease in endothermic animals, with cardiovascular effects that were first recognized in southern sea otters. Over the last 20 years, DA toxicosi
Authors
Megan E. Moriarty, M. Tim Tinker, Melissa Miller, Joseph A. Tomoleoni, Michelle M. Staedler, Jessica A. Fujii, Francesca I. Batac, Erin M. Dodd, Raphael M. Kudela, Vanessa Zubkousky-White, Christine K. Johnson
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Western Ecological Research Center (WERC)

Canine distemper virus in the sea otter population (Enhydra lutris) in Washington State, USA

Before 2001, all serosurveys for morbilliviruses in sea otters (Enhydra lutris) in California, Washington, and Alaska, USA, documented a 0% seroprevalence. The first published serologic detections of morbillivirus in sea otters occurred in 2001–02 in live-captured Washington sea otters, with a documented 80% seroprevalence. We conducted a retrospective study of sea otter cases from 1989 to 2010 co
Authors
Nancy Thomas, C. LeAnn White, Jeremiah Saliki, Krysten L. Schuler, Deanna Lynch, Ole Nielsen, J.P. Dubey, Susan Knowles
By
Ecosystems Mission Area, National Wildlife Health Center

Emergence of a zoonotic pathogen in a coastal marine sentinel: Capillaria hepatica (syn. Calodium hepaticum)-associated hepatitis in southern sea otters (Enhydra lutris nereis)

Capillaria hepatica is a globally distributed zoonotic nematode parasite that most commonly infects feral and native rats. Soil contact, pica, and living in close proximity to rat populations are risk factors for human infection. Larval nematodes and eggs that were morphologically consistent with C. hepatica were observed microscopically in livers of stranded southern sea otters (Enhydra lutris ne
Authors
Melissa A. Miller, Padraig J Duignan, Erin Dodd, Francesca Batac, Michelle M. Staedler, Joseph A. Tomoleoni, Michael J. Murray, Heather Harris, Chris Gardiner
By
Ecosystems Mission Area, Western Ecological Research Center (WERC)

Spatial epidemiological patterns suggest mechanisms of land-sea transmission for Sarcocystis neurona in a coastal marine mammal

Sarcocystis neurona was recognised as an important cause of mortality in southern sea otters (Enhydra lutris nereis) after an outbreak in April 2004 and has since been detected in many marine mammal species in the Northeast Pacific Ocean. Risk of S. neurona exposure in sea otters is associated with consumption of clams and soft-sediment prey and is temporally associated with runoff events. We exam
Authors
Tristan Burgess, M. Tim Tinker, Melissa A. Miller, Woutrina A. Smith, James L. Bodkin, Michael J. Murray, Linda M. Nichol, Justin A. Saarinen, Shawn E. Larson, Joseph A. Tomoleoni, Patricia A. Conrad, Christine K. Johnson
By
Ecosystems Mission Area, Western Ecological Research Center (WERC)

We are developing advanced tools for disease diagnosis, surveillance, risk assessment and control to support management of wildlife diseases.

Marine Mammal Disease Research

link
Sea otter Elkhorn Slough National Estuarine Research Reserve (WERC)

Population Biology and Behavior of Sea Otters

WERC's sea otter researchers are developing and utilizing a variety of methodological and analytical tools to understand the causes of biological and ecological trends in sea otter populations, and to predict the ecological consequences of management practices on these populations and their ecosystems.
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Species Management Research Program, Western Ecological Research Center (WERC)
link

Population Biology and Behavior of Sea Otters

WERC's sea otter researchers are developing and utilizing a variety of methodological and analytical tools to understand the causes of biological and ecological trends in sea otter populations, and to predict the ecological consequences of management practices on these populations and their ecosystems.
Learn More
link
WERC Sea otter research in Big Sur, California

California Sea Otter Stranding Network

The California Sea Otter Stranding Network is part of the USGS effort to monitor southern sea otters (Enhydra lutris nereis) and provide data to the U.S. Fish and Wildlife Service. WERC's sea otter team works with multiple institutions and partners to report, recover, and examine stranded sea otters. In addition, instructions on how to report a stranded sea otter are included in this webpage.
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Species Management Research Program, Western Ecological Research Center (WERC)
link

California Sea Otter Stranding Network

The California Sea Otter Stranding Network is part of the USGS effort to monitor southern sea otters (Enhydra lutris nereis) and provide data to the U.S. Fish and Wildlife Service. WERC's sea otter team works with multiple institutions and partners to report, recover, and examine stranded sea otters. In addition, instructions on how to report a stranded sea otter are included in this webpage.
Learn More

Explore our science using the data below.

Sea Otter Survey Data, Carcass Recovery Data, and Blood Chemistry Data from Southwest Alaska

Three data sets are included here to aid in assessment of the sea otter population collapse in southwest Alaska. One data set consists of results of sea otter surveys conducted between 1959 and 2015 at Bering Island, Russia and a selection of western Aleutian Islands in Alaska. Sea otter counts are reduced to a comparable value of otters per linear kilometer. Another data set consists per-capita a
By
Western Ecological Research Center (WERC)

Necropsy reference number and summary collection information for Washington state population of northern sea otters examined during 1989-2010

Morbillivirus epidemics in marine mammals first gained prominence in 1988 when an outbreak of phocine distemper virus (PDV) occurred in European harbor seals (Phoca vitulina vitulina). Prior to 2001, all serosurveys for morbilliviruses in sea otters (Enhydra lutris) in California, Washington and Alaska documented a 0% seroprevalence. The first published serodetections of morbillivirus in sea otter
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, National Wildlife Health Center

Explore our science using the publications below.

New insights into dietary management of polar bears (Ursus maritimus) and brown bears (U. arctos)

Although polar bears (Ursus maritimus) and brown bears (U. arctos) have been exhibited in zoological gardens for centuries, little is known about their nutritional needs. Multiple recent studies on both wild and captive polar bears and brown bears have found that they voluntarily select dietary macronutrient proportions resulting in much lower dietary protein and higher fat or digestible carbohydr
Authors
Charles T. Robbins, Troy N Tollefson, Karyn D. Rode, Joy Erlenbach, Amanda J. Ardente
By
Ecosystems Mission Area, Alaska Science Center

An integrated population model for southern sea otters

Southern sea otters (Enhydra lutris nereis) have recovered slowly from their near extinction a century ago, and their continued recovery has been challenged by multiple natural and anthropogenic factors. Development of an integrated population model (IPM) for southern sea otters has been identified as a management priority, to help in evaluating the relative impacts of known threats and guide best
Authors
M. Tim Tinker, Lilian P. Carswell, Joseph A. Tomoleoni, Brian B. Hatfield, Michael D. Harris, Melissa A. Miller, Megan E. Moriarty, Christine K. Johnson, Colleen Young, Laird A. Henkel, Michelle M. Staedler, A. Keith Miles, Julie L. Yee
By
Ecosystems Mission Area, Western Ecological Research Center (WERC)

Energetic and health effects of protein overconsumption constrain dietary adaptation in an apex predator

Studies of predator feeding ecology commonly focus on energy intake. However, captive predators have been documented to selectively feed to optimize macronutrient intake. As many apex predators experience environmental changes that affect prey availability, limitations on selective feeding can affect energetics and health. We estimated the protein:fat ratio of diets consumed by wild polar bears us
Authors
Karyn D. Rode, Charles T. Robbins, Craig A. Stricker, Brian D. Taras, Troy N Tollefson
By
Ecosystems Mission Area, Alaska Science Center, Fort Collins Science Center

Sea otter population collapse in southwest Alaska: Assessing ecological covariates, consequences, and causal factors

Sea otter (Enhydra lutris) populations in southwest Alaska declined substantially between about 1990 and the most recent set of surveys in 2015. Here we report changes in the distribution and abundance of sea otters, and covarying patterns in reproduction, mortality, body size and condition, diet and foraging behavior, food availability, health profiles, and exposure to environmental contaminants

Authors
M. Tim Tinker, James L. Bodkin, Lizabeth Bowen, Brenda Ballachey, Gena Bentall, Alexander Burdin, Heather Coletti, George G. Esslinger, Brian B. Hatfield, Michael C. Kenner, Kimberly A. Kloecker, Brenda Konar, A. Keith Miles, Daniel Monson, Michael J. Murray, Ben Weitzman, James A. Estes
By
Ecosystems Mission Area, Alaska Science Center, Western Ecological Research Center (WERC)

Exposure to domoic acid is an ecological driver of cardiac disease in southern sea otters

Harmful algal blooms produce toxins that bioaccumulate in the food web and adversely affect humans, animals, and entire marine ecosystems. Blooms of the diatom Pseudo-nitzschia can produce domoic acid (DA), a toxin that most commonly causes neurological disease in endothermic animals, with cardiovascular effects that were first recognized in southern sea otters. Over the last 20 years, DA toxicosi
Authors
Megan E. Moriarty, M. Tim Tinker, Melissa Miller, Joseph A. Tomoleoni, Michelle M. Staedler, Jessica A. Fujii, Francesca I. Batac, Erin M. Dodd, Raphael M. Kudela, Vanessa Zubkousky-White, Christine K. Johnson
By
Ecosystems Mission Area, Biological Threats and Invasive Species Research Program, Western Ecological Research Center (WERC)

Canine distemper virus in the sea otter population (Enhydra lutris) in Washington State, USA

Before 2001, all serosurveys for morbilliviruses in sea otters (Enhydra lutris) in California, Washington, and Alaska, USA, documented a 0% seroprevalence. The first published serologic detections of morbillivirus in sea otters occurred in 2001–02 in live-captured Washington sea otters, with a documented 80% seroprevalence. We conducted a retrospective study of sea otter cases from 1989 to 2010 co
Authors
Nancy Thomas, C. LeAnn White, Jeremiah Saliki, Krysten L. Schuler, Deanna Lynch, Ole Nielsen, J.P. Dubey, Susan Knowles
By
Ecosystems Mission Area, National Wildlife Health Center

Emergence of a zoonotic pathogen in a coastal marine sentinel: Capillaria hepatica (syn. Calodium hepaticum)-associated hepatitis in southern sea otters (Enhydra lutris nereis)

Capillaria hepatica is a globally distributed zoonotic nematode parasite that most commonly infects feral and native rats. Soil contact, pica, and living in close proximity to rat populations are risk factors for human infection. Larval nematodes and eggs that were morphologically consistent with C. hepatica were observed microscopically in livers of stranded southern sea otters (Enhydra lutris ne
Authors
Melissa A. Miller, Padraig J Duignan, Erin Dodd, Francesca Batac, Michelle M. Staedler, Joseph A. Tomoleoni, Michael J. Murray, Heather Harris, Chris Gardiner
By
Ecosystems Mission Area, Western Ecological Research Center (WERC)

Spatial epidemiological patterns suggest mechanisms of land-sea transmission for Sarcocystis neurona in a coastal marine mammal

Sarcocystis neurona was recognised as an important cause of mortality in southern sea otters (Enhydra lutris nereis) after an outbreak in April 2004 and has since been detected in many marine mammal species in the Northeast Pacific Ocean. Risk of S. neurona exposure in sea otters is associated with consumption of clams and soft-sediment prey and is temporally associated with runoff events. We exam
Authors
Tristan Burgess, M. Tim Tinker, Melissa A. Miller, Woutrina A. Smith, James L. Bodkin, Michael J. Murray, Linda M. Nichol, Justin A. Saarinen, Shawn E. Larson, Joseph A. Tomoleoni, Patricia A. Conrad, Christine K. Johnson
By
Ecosystems Mission Area, Western Ecological Research Center (WERC)
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